What is atelectasis?

Atelectasis refers to a condition characterized by a partial or total collapse of the lung or a section of the lung. This can occur when the air sacs (alveoli) in the lungs become deflated, leading to reduced gas exchange and resulting in decreased oxygen levels in the blood. The collapse can be due to a variety of factors such as blockage of the air passages, pressure from outside the lung, or insufficient surfactant, a substance that helps keep the alveoli open.

Having a clear understanding of atelectasis is important in the medical field, especially when treating patients with respiratory issues. Identifying and addressing atelectasis can help improve a patient's breathing and overall lung function.

The other choices describe conditions that do not apply to atelectasis. A complete expansion of the lungs would indicate healthy lung function, not a collapse. An increase in lung capacity would suggest better lung performance, and an obstruction in the airways is a separate condition that may contribute to atelectasis but does not define it.